This application is the national phase under 35 U.S.C. xc2xa7 371 of PCT International Application No. PCT/JP99/02982 which has an International filing date of Jun. 3, 1999, which designated the United States of America.
The present invention relates to a surfactant composition comprising a nonionic surfactant. More specifically, the present invention relates to a non-liquid detergent composition formulated with the surfactant composition.
A nonionic surfactant having a melting point of 30xc2x0 C. or less is excellent in the deterging performance against sebum stains. However, since the nonionic surfactant is in a liquid or paste-like state at an ordinary temperature, it is difficult to formulate the nonionic surfactant in a non-liquid detergent such as a powdery detergent.
In order to solve the above-mentioned problems, there is provided, for instance, a process comprising spray-drying a detergent slurry comprising a nonionic surfactant to powder the slurry. However, from the viewpoints of lowered heat resistance and powder properties of the nonionic surfactant, a large amount of the nonionic surfactant cannot be formulated, so that sufficient detergency could not be obtained.
In addition, there is a process comprising supporting a composition comprising a nonionic surfactant in a powder, to give a powdery detergent. In this case, the composition is supported by surface adsorption to the powder and capillary force of the powder, so that there arise problems in the bleed-out property of the nonionic surfactant and the caking ability.
Japanese Patent Laid-Open No. Sho 52-110710 discloses a process for preparing a powdery detergent in which a surfactant composition mainly comprises a nonionic surfactant which is in a liquid or semi-solid state at room temperature. However, it neither discloses nor suggests any means for improvements in the suppression of the bleed-out of the nonionic surfactant and the anti-caking property. Therefore, when the surfactant composition is used for the preparation of a detergent particle, there is a problem in its quality.
In addition, an anionic surfactant having sulfonate group is excellent in the deterging performance and the foaming ability, and further the anionic surfactant is extremely useful from the viewpoints of high stability and low price.
In consideration of the aspect of the deterging performance, the anionic surfactant having sulfonate group possesses especially high deterging performance against hydrophilic stains such as dirt stains. Therefore, a high deterging performance can be exhibited against a wide variety of stains by combining a nonionic surfactant which is excellent in the deterging performance for sebum stains with the anionic surfactant having sulfonate group.
In addition, since a nonionic surfactant generally has a low foaming ability, a desired foaming ability can be obtained by the combined use of the nonionic surfactant with an anionic surfactant having sulfonate group, which is excellent in the foaming ability.
Japanese Patent Laid-Open No. Sho 63-110292 discloses a surfactant composition usable for the preparation of a powdery detergent, wherein the surfactant composition has easy flowability capable of being sprayed in a range of 20xc2x0 to 80xc2x0 C. and comprises a nonionic surfactant and an alkylbenzenesulfonate or alkyl sulfate, and water. However, in the combination of the nonionic surfactant with the alkylbenzenesulfonate, the bleed-out of the nonionic surfactant cannot be suppressed, so that there is a great concern on the lowering of the anti-caking property. In addition, when the alkyl sulfate is used, there arises a problem in the stability of the sulfuric acid ester group. Also, there arise such problems that the conveyability is poor owing to the fact that the viscosity tends to increase, and that the handleability during detergent preparation is poor owing to the fact that its adhesion is high in the mixing step with a powdery raw material.
In other words, it is required to have such properties in combination as a surfactant composition used in the preparation of a non-liquid detergent, that the surfactant composition has a sufficiently low viscosity in a temperature range capable of preparing the detergent, that a non-liquid detergent composition in which a surfactant composition is supported does not cause the bleed-out of the nonionic surfactant, and that caking as caused by particle deformation does not take place when used for a powdery detergent composition by hardening the surfactant composition in a temperature range during storage of the detergent.
Accordingly, an object of the present invention is to provide a surfactant composition having such properties in combination that the surfactant composition has a sufficiently low viscosity which can be easily handled in a temperature range during preparation, preferably 90xc2x0 C. or less, in a process for preparing a non-liquid detergent composition, and that the surfactant composition is hardened for the purposes of improvements in the suppression of the bleed-out of the nonionic surfactant and in the hardness of the detergent composition in a temperature range during storage of the detergent composition. Further, it is to provide a detergent composition comprising the surfactant composition in which the bleed-out of the nonionic surfactant is small, and the hardness of the detergent composition is high, so that the detergent composition is excellent in the anti-caking property, and a process for preparing the same.
Specifically, the present invention relates to:
[1] a surfactant composition which is capable of being formulated for use in a non-liquid detergent composition, the surfactant composition comprising:
a) a nonionic surfactant having a melting point of 30xc2x0 C. or less;
b) an anionic surfactant having sulfonate group; and
c) an immobilization agent for a) component,
xe2x80x83wherein b) component is formulated in an amount of from 0 to 300 parts by weight, based on 100 parts by weight of a) component, and wherein c) component is formulated in an amount of from 1 to 100 parts by weight, based on 100 parts by weight of a) component, and wherein the surfactant composition has:
(1) a temperature range that a viscosity of the composition is 10 Paxc2x7s or less at a temperature equal to or higher than a pour point of the surfactant composition; and
(2) a temperature range that a penetrating hardness of the composition is 100 g/cm2 or more in a temperature range between a temperature lower than the pour point of the composition and a temperature higher than the melting point of a) component; and
[2] a process for preparing a non-liquid detergent composition comprising the step of mixing the surfactant composition of item [1] above with a powdery raw material, under a temperature condition such that a viscosity of the surfactant composition is 10 Paxc2x7s or less.